Original subtitles

--Captions by vitac-- www.Vitac.Com

captions paid for by discovery communications, inc.

Narrator: Today on "how it's made"...

Compact discs...

...mozzarella cheese...

...pantyhose...

...and fluorescent tubes.

Today there's virtually no limit

to the information we can store on compact discs.

Millions of bits of data representing words, numbers,

music, graphics, or even video can be stored on the discs.

Let's take a "spin" through a cd factory.

Compact discs are copies made

from an original glass master disc.

A thin plate of glass is first placed in this unit,

which brushes the surface clean.

Cleaning is done with de-ionized water

and a small goat-hair brush.

The excess water is eliminated

by the rapid rotation of the disc.

The disc then goes into this surface analyzer,

where a laser beam inspects the cleanliness of the surface.

At this stage, two chemicals are applied --

a primer and a photoresistant coating.

This operation is done

at a temperature of 70 degrees fahrenheit

and lasts three minutes.

The disc is carefully retrieved from the apparatus.

Then the photoresistant coating dries in an oven for 30 minutes.

This developer has two spouts.

One applies a de-ionized water, and the other sprays a solution

to develop the data etched on the glass.

The information is now engraved on the disc.

Then the disc is placed in this metal-coating equipment.

The next step consists of applying a thin coating

of nickel and vanadium.

This electroforming process results in the master

from which discs will be made.

The etched glass is immersed in a chemical solution

for 70 minutes.

Then the plated piece is removed, thus obtaining a die.

The die is sent off for finishing.

It is stamped out into the desired shape.

The excess material is recycled.

Next, the compact discs will be fabricated

from this master unit.

Here we clearly see the stamping-out technique.

The master is taken out.

A technician peels off the film

which protected the data etched onto the die.

After a visual inspection,

the die is sent to the pressing department.

The die is delicately installed in the mold,

which will form compact discs.

Discs are made from a very special plastic

called "polycarbonate."

The mold is closed,

and liquid polycarbonate is injected into the die.

It comes out as a small, hard, translucent disc.

It is now ready to be metal-coated

so it can be read by a compact-disc reader.

A robotic arm lifts the disc from the mold

and places it on these supports.

This metallizing process is extremely short and very simple,

taking but a second.

It consists of covering the plastic disc

with a very thin coating of aluminum.

Here we see the inside of the mold,

where the aluminum coating is applied.

In this facility, almost everything is automated,

helping them produce over 100,000 compact discs per day.

Protecting the surface of the disc is essential,

so a coat of varnish is applied.

This also helps silk screening stick to the surface.

Ultraviolet lamps quickly dry the varnish.

And here in the pressing room, they apply the label.

This step is also very fast

since the machine prints 70 discs in 60 seconds.

Once the silk-screening is completed,

the finished discs leave for packaging.

Narrator: In a sandwich, as a topping, or all by itself,

cheese has always been a popular food.

This dairy product goes back thousands of years,

and it's always started with three basic ingredients --

milk, curds, and whey.

Just ask little miss muffet.

Like all cheeses, mozzarella starts from milk.

To assure good milk quality,

the interior and exterior of milk-transport trucks

must be washed after being emptied.

A tank such as this one

can carry an average of 8,000 gallons of raw milk

at temperatures between 37 and 39 degrees fahrenheit.

Raw milk destined for cheesemaking

contains 3.8% fats and 3.3% proteins.

They store the milk and whey, a milk by-product,

in these immense silos,

each with a capacity of 59,000 gallons.

This milk separator extracts surplus cream

to adjust the percentage of fat

according to the type of cheese to be made.

Fabrication begins with this tank,

which feeds the pasteurizer.

Pasteurization sterilizes beverages

which can easily ferment.

Milk samples are drawn off

to accurately determine their milk-fat and protein content.

Tests are carried out in this laboratory,

where they impose controls.

These test tubes contain milk samples

which will undergo microbiological analysis.

Milk quality must be impeccable.

This is a curdler with a capacity of 6,600 gallons.

Here milk and other essential ingredients are introduced,

such as the enzyme, rennet, that curdles the milk.

This mix must be well-stirred and cooked.

The agitators are used to cut the whey into little lumps.

This step takes about 30 minutes.

The temperature of the tanks

depends on the type of cheese they're making.

Agitators continue stirring the milk.

Once cooking is done,

the whey is pumped onto tables to be drained.

It stays there for about 25 minutes.

The solid and the liquid are now well-separated.

The liquid we see draining is called the "lactoserum."

The lactoserum will be concentrated

and transformed into milk by-products.

The water has been almost entirely extracted,

and the cheese particles are now sufficiently dry.

This large automated blade

then moves cheese particles towards the next step --

the molder.

In the molder, the cheese is cut up

before being carried to the cooker --

the final processing step.

It appears that this mozzarella has just the right texture.

The cheese finally arrives at the molder,

which will give it the proper shape.

Each mold has a 5 1/2-pound capacity and is rectangular.

Brine, a salt solution, cools and salts the cheese blocks.

The blocks are unmolded and fall into a brine tank.

The cheese blocks will remain in another brine solution

for a while.

Then they're carried by a conveyor towards another tank,

where they will be immersed for 4 to 10 hours

at a temperature of 36 degrees fahrenheit.

Sprays of brine remove the foam

which forms at the surface of the tank.

The 8,000 gallons of milk

we saw coming in by truck at the beginning

have enabled the factory to produce 1,400 blocks of cheese

in 8 to 12 hours.

Finally, the cheese blocks are vacuum-packed

and ready for shipment.

Narrator: There was a time when women wore silk stockings.

Then came the invention of pantyhose,

a cheaper, more convenient alternative.

Pantyhose are knitted from strands of raw nylon.

It's no "stretch" of the imagination to say

that when they go on sale, there's usually a "run" on them.

Making a nylon stocking takes only a few minutes.

However, it's a complex operation

that involves the knitting of five to eight threads

as fine as a hair.

The threads, usually nylon and spandex,

are used along with elastic.

Sometimes polyester or cotton are added.

The knitting machine goes into action.

This one fashions a tube for sheer stockings in 90 seconds.

In three minutes, it makes a tube for tights.

Its speed is adjusted according to the product being made,

varying between 750 and 1,200 revolutions per minute.

Once the tube is knitted, it is sucked up and lands in a bag,

where it will be inspected.

More than 500 machines share the work,

each making a specific model.

The two ends must now be joined.

This automated machine assembles the two tubes together

to form the pantyhose.

Then scissors cut the pantyhose,

a necessary step in production of a pair.

This opening is enlarged to allow for sewing,

which will join the two tubes at the top of the leg.

The label with the size or brand name

is sewn in place in 10 seconds by this robotic machine.

At this pace, it sews on 4,800 labels in 8 hours.

Installing a gusset requires some preparation.

Scissors makes a hole at the joining point.

Then the stocking is turned inside out by suction

so certain stitching can be done on the inside.

Thus, these stitches will be less visible.

Now the foot must be sewn.

This robotic machine places the foot in position.

Then a sewing machine makes stitches

at the same time it cuts away excess material.

This step takes only 10 seconds.

Then the pantyhose is turned right side out,

again using suction.

Everything is ready for installation of the gusset.

The pantyhose is placed in a tub and taken to this department.

The stocking is again suctioned

and placed on a gusset machine by the operator.

This method assures that the gusset will be well-centered

without a pleat.

Putting in the gusset is the final operation in the process.

A precut piece of cotton

is slid into the space reserved for the gusset

and automatically sewn in.

Only aesthetic touches remain,

such as adding a little color to the pantyhose.

They're placed in this machine,

which has a large drum with four compartments

and a 99-pound capacity.

The pantyhose are washed in soapy water,

then immersed in dye.

Temperature climbs gradually to 200 degrees fahrenheit.

After a 5-minute rinsing cycle, a softener is added.

This process takes 2 1/2 hours.

Once dried, they proceed to inspection.

The pantyhose is placed onto a form

which stretches it to allow inspection

for any imperfections.

If all is well,

the pantyhose is transferred onto another metal form,

where it will be pressed.

The pantyhose's position is guided by a magic eye.

The pantyhose is then carried toward a steam room,

where it will stay for 2 1/2 seconds

before being dried in 7 1/2 seconds at 280 degrees.

They fold and pack 420 pantyhose per hour

and make 180,000 pairs per day.

Narrator: Throughout the ages, artificial light

has let people extend the convenience of daylight

long after the sun goes down.

Fluorescent tubes are more energy-efficient

than light bulbs.

That's probably why they've become a "fixture," so to speak,

in stores, factories, and offices.

Once, the only source of light was the flame of fire

in the forms of torch, candle, and oil lamps.

It remained so right up until the 19th century,

when gaslight made its first appearance around 1840.

Almost 40 years later,

Thomas Edison invented his famous incandescent light bulb.

In 1909,

the frenchman Georges Claude developed the fluorescent tube,

a light that remains unaltered to this very day.

Did you know that Mercury allows us to see in the dark?

The production of fluorescent lamps is highly complex.

The fabrication process starts with glass tubes

that have been meticulously cleaned with warm water

to remove dirt and impurities.

Then the tubes have to be specifically shaped

with a folder-shaper.

They're heated for 30 seconds,

then quickly curved using a template.

This automated machine can bend 14 tubes a minute.

The bent tubes go into the coating chamber,

where a thin coat of phosphorus

is applied to their inner surfaces.

Phosphorus produces light by transforming ultraviolet photons

generated by the ionization of Mercury.

The surplus phosphorus is removed

from the ends of the tube to facilitate sealing.

They now move to the electrical components.

The cathode mount is made in this auto mount.

Here, they make the wire

that will carry the current from the mount.

The wire carrying the current is shaped.

And here, the wire is heated.

This prepares it for the next step.

It's essential to prevent the cathode coating

from spreading to the prongs.

The filaments are inserted into their mounts.

The emissive substance plays a crucial role.

When heated, it emits electrons,

which participate in producing light.

The emissive substance is actually this liquid.

The wiring mount is transferred from the auto mount

to the sealing machine.

At this stage,

the wiring mount and the glass tube are joined.

Sealing is done at a very high temperature.

One important step remains.

This is where the glass tube is emptied of air

and filled with gas.

This machine also decarbonizes the tube

and introduces the drop of Mercury

essential for producing light.

Once the very tiny drop of Mercury

is injected into the tube,

the fluorescent lamp is almost completed.

But one step remains.

This threader positions the wires

for insertion of the tube cap,

which establishes electrical contact.

The tube cap is placed into position

in preparation for sealing.

The cap must be securely attached

and installed in a watertight manner

to eliminate any risk of leaking.

The capper permanently seals the cap onto the tube,

and it's all finished.

Each lamp is tested on a large testing wheel

to verify its quality and performance.

Once the meticulous inspection is over,

the fluorescent lamps are carried

to the packaging department.

A robotic machine handles the lamps

and places them into the packages.

The glass tubes have now become fluorescent lamps.

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